Embodiments of the present disclosure relate to a heat transfer assembly required for cooling a heat emitting device, such as a power electronic devices or for cooling multiple heat emitting devices.
Traditionally in liquid cooling of heat emitting devices such as the power electronic devices, the devices are mounted on a cooling plate, referred generally as a cold-plate which is subjected to an internal, single-phase fluid flow of a liquid coolant. Heat generated by the electronic device is conducted through three layers that include, an electronic device baseplate, a Thermal Interface Material (TIM), and the cold-plate body. Finally, the heat is convected into the liquid coolant and transported downstream, to be rejected to ambient.
There exist different solutions that provide different structures to achieve the cooling described herein above. Some improvements to this cooling also include direct cooling solutions where the TIM layer and the cold-plate body conduction layers are removed and the coolant flow is applied to the baseplate of the power electronic device.
However, the direct cooling designs often suffer from leak related issues that cause damage to the power electronic device and is a serious reliability concern in the manufacturing of these cooling solutions. Further, some of these designs also suffer from coolant flow distribution issues. Usually, a single pump is used to drive the coolant through multiple flow paths. In several designs, the flow is imbalanced, when one path has a different resistance to coolant flow than the others. Another concern is a water hammer effect in some designs which arises when a high velocity flow bypasses some paths, and creates a much higher flowrate through the final path.
Thus, effective sealing and proper flow distribution of the coolant continue to be some challenges in the cooling solutions for heat emitting devices.